The PLA identified two US aircraft and 10 Japanese aircraft. The US planes made two sorties across the zone, while the Japanese made seven.

Seoul said it had filed an official report informing China about its plan to include Ieo Island as part of its air defence zone, renewing tensions over the submerged rock that has been administered by Seoul but is now covered in Beijing’s new air zone, South Korea’s Chosun Ibo reported yesterday.

The small rock, which is about 3.4 metres under water, is now home to a research station built by South Korea. Beijing also claims the rock.

In June, an official from China’s State Oceanic Administration told Chinese media that Beijing would regularly patrol around Ieo with ships and surveillance aircraft.

Japan’s air defence zone also covers Ieo. But this does not pose any issue for South Korea as Japan is not a claimant, according to Scott Harold, an associate political scientist at the Rand Corporation.

Among signs of growing anger, the Taiwanese government said it would complain after Beijing failed to consult Taipei about declaring the zone in the East China Sea.